Jest for the pun of it.

Antanaclasis is a type of pun in which a word is repeated, and with each repetition it's context shifts from one meaning to another.

An example from Shakespeare:
O, cursed be the hand that made these holes!
Cursed be the heart that had the heart to do it!
Cursed be the blood that let his blood from hence!
--Richard III, Act I, Scene ii, Lines 13-15